represents the elementary function of the 2D wavelet rotated by an angle \(\theta \) . Using the Gabor elementary function, the entire family of Gabor wavelets can be generated. Lee et al. [1]} have derived a specific class of 2D-Gabor wavelets which is used in this paper to obtain a set of Gabor wavelets to process the retinal images. The Gabor wavelet which satisfies the neurophysiological restraint of simple cells is defined as

\(\psi (x,y,{\omega _0},\theta ,K ) = &\frac{{{\omega _0}}}{{\sqrt{2\pi } K }}\exp \left( { - \frac{{\omega _0^2}}{{8{K^2}}}\left( {4{{(xcos\theta + y\sin \theta )}^2} + {{( - xsin\theta + ycos\theta )}^2}} \right)} \right)\\&\cdot \left[ {\exp \left\lbrace  {i{\omega _0}\left( {xcos\theta + y\sin \theta } \right)} \right\rbrace  - \exp \left( { - \tfrac{{{K^2}}}{2}} \right)} \right]\nonumber \) 
